1. Field of the Invention
The present invention relates in general to a charge coupled device package used in electric equipment, such as an integrated camera and video cassette system, and more particularly to a charge coupled device package with a glass lid, which is covered with and sealed by the glass lid which lid is capable of transmitting an image light to a light reception part of a charge coupled device.
2. Description of the Related Art
With reference to FIG. 1, there is shown a known charge coupled device package with a glass lid where the glass lid of a predetermined size covers and seals a charge coupled device, Here, as well known to those skilled in the art, the charge coupled device is used to convert an image light into an electric signal. The known charge coupled device package with a glass lid (hereinafter, referred to simply as "the glass lid type CCD package") includes a ceramic package having a ceramic body or a package body 4 provided with a cavity 4a of a predetermined diameter and a predetermined depth. In order to manufacture the ceramic package, a plurality of metal lines or lead fingers 5 are arranged on the package body 4 at opposite sides of the cavity 4a such that the lead fingers 5 are spaced apart from each other by a predetermined interval. Thereafter, a ceramic layer, having a predetermined thickness and a predetermined width, is applied on the lead fingers 5 on each of the sides of the package body 4 prior to burning the package body 4.
A plurality of outleads 6 are connected to outer ends of individual lead fingers 5. The outleads 6 are also connected to the opposite side walls of the package body 4 through bra-Ting metals 6' respectively. The charge coupled device 1 (hereinafter, referred to simply as "the CCD"), having a light reception part 1a on its upper center, is bonded to the upper center of the cavity 4a of the CCD package body 4. The CCD 1 is also provided on its opposite sides with a plurality of bond pads 2, each of which is connected to an inner end of each of the lead fingers 5 by a metal wire 3. The package body 4 is covered with and sealed by a glass lid 7 through which an outside image light is transmitted to the light reception part la of the CCD 1.
In order to bond the glass lid 7 to the package body 4, a bonding agent having a lower melting point is conventionally used.
In application, the known glass lid type CCD package is mounted on a circuit board (not shown) such that the outleads 6 of the package are connected to signal terminals of a signal processing circuit (not shown) of the circuit board and conventionally used as an optical element of electronic equipment, particularly of an integrated camera and video cassette recorder system, a so-called camcorder. In operation, the optical image light from the camera lens is transmitted through the glass lid 7 and received by the light reception part 1a of the CCD 1. Upon reception of the image light, the CCD 1 converts the image light into an appropriate electric signal which is in turn outputted to the signal processing circuit through the bond pads 2 of the CCD 1, the metal wires 3, the lead fingers 5 and the outleads 6 in this order.
In the drawing, the reference numeral 9 denotes a bonding part for bonding the CCD 1 to the bottom surface of the cavity 4a of the package body 4.
Turning to FIG. 2, there is shown a flowchart of a process for manufacturing the known glass lid type CCD package. In order to manufacture the known glass lid type CCD package, a wafer forming step 110 of the ceramic package body 4 is first carried out. The package body 4 is formed such that it has the cavity 4a on its upper surface. The plurality of lead fingers 5 are, thereafter, arranged on the package body 4 at the opposite sides of the cavity 4a and applied with the ceramic layer, having the predetermined thickness and the predetermined width, thereby producing the package body 4. This package body forming step is followed by a die attaching step 130 wherein the CCD 1, prepared by the step 120 of sawing the wafer, is bonded to the center of the bottom surface of the cavity 4a of the package body 4. Thereafter, the plurality of the bond pads 2 of the CCD 1 are connected to the inner ends of the lead fingers 5 through the metal wires 3, respectively, thereby accomplishing a wire bonding step 140. The wire bonding step 140 is followed by a glass lid sealing step 150 wherein the glass lid 7 is bonded to the upper surface of the package body 4 to seal the cavity 4a. The process for manufacturing the glass lid type CCD package further includes a trimming step 160 and a marking step 170 which are performed in this order after the glass lid sealing step 150. Here, a green tape forming and a screen printing are carried out in this order to arrange the lead fingers 5 on the package body 4.
As noted from the above description, in manufacturing the known glass lid type CCD package, it is required to form the package body using the ceramic material while arranging the plurality of metal lines or the lead fingers on predetermined positions of the package body. Also, the plurality of outlands should be bonded to the opposite side walls of the package body and connected to the outer ends of the lead fingers after the burning of the package body, respectively. Thus, the known glass lid type CCD package has a problem in that it requires a complex manufacturing process, involves a larger capital investment and requires a longer manufacturing time, so that it is not suitable for mass production.
In addition, the known glass lid type CCD package requires a critical cleanness control in its manufacturing process since it has the CCD, adapted for converting the image light into the electric signal, thereby requiring good care in assembling the semiconductor device. Another problem of the known glass lid type CCD package is that it does not achieve the recent trend of compactness of the semiconductor device. Furthermore, the known glass lid type CCD package is limited in reducing a lead pitch (presently reduced to 50 mil) of its outleads, thereby providing no semiconductor device having a fine pitch.